Indonesia’s Jakarta-Bandung High Speed Railway (HSR) made another major progress on Sunday with Tunnel 7, the first over 1-km tunnel in the project, being bored through.
The 1.285-km tunnel is the third completed tunnel after Walini Tunnel and Tunnel 5.
The body of Tunnel 7 consists of clay, mudstone and andesite, and 80 percent of the geology is V-grade surrounding rock.
The maximum buried depth is 77.4 meters and buried depth of the tunnel under 30 meters accounts for 93 percent of the project. Based on the various features of the geological condition at different sections, the technicians applied Three-step Temporary Inverted Arch Method, Three-step Temporary Transverse Support Excavation Method, CRD (Completely Randomized Designs) Method and other technologies to ensure the construction progress and safety.
The China Railway Group Limited (CREC) Indonesia has overcome many difficulties such as shallow burying, biased pressure, inlet road relocation, land sliding and COVID-19 pandemic, strictly following the design and regulation with reasonable technology methods and innovation.
During the construction process, 260 well-trained Indonesian technicians have played an important role.
Since the outbreak of COVID-19, the project department of CREC Indonesia has taken effective measures to protect staffs from the virus as well as to support logistics needs, which laid a solid foundation for the completion of Tunnel 7.
According to the department, they will continue to promote project construction with high quality and efficiency in the future.